the_speculative_evolutionfandomcom-20200214-history
Champion speciators
Champion speciators are usually prolific, very hardy, a generalistic species, must be (or was) widespread, and must have a diverse and random gene pool. In other words, they have a lot of babies, can find a way to live most anywhere, eat a variety of different foods, obviously must have been spread over a large area, and must be able to have mutations out of nowhere that could be beneficial to the species. Supertaxa are a group of animals that rapidly evolve and once they evolve they rarely go extinct (high origination rates & low extinction rates). Endemic species (high origination rates but high extinction rates) are also (usually) prolific but are (usually) so specialized to the point it is hard to mutate their way out of extinction. The last group, living fossils are different than either earlier two, (low extinction rates but also low origination rates) the evolve as a generalist and it takes them quite a bit of time to specialize (even by geological standpoints). Endemic taxa are champion speciators, but they need to survive long enough to speciate. Supertaxon are obviously the champion speciators. Let's consider the orders of land vertebrates, their number of species and the timespan they have existed on Earth: we can compare their capacity to produce species by measuring how many species they produced, as an average, for each million of years (Ma) of evolution. These are the orders that have a species/time ratio above 5 (data from Wikipedia): Human Impact Of course, humans impact what the champion speciators are in interesting ways. Induced extinction might be the obvious example, but this isn't actually necessarily the biggest impact, because many of the champion speciators aren't especially vulnerable to all-out extinction. For instance, while individual species of carnivorans (such as big cats and many canines) might be vulnerable, carnivorans also include foxes, which adapt well to urban expansion, and coyotes, which are notable for being nearly impossible to even dent in numbers. While the Socorro dove might be extinct in the wild, pigeons are ubiquitous in many cities. While humans can definitely cause losses in the supertaxa, we are unlikely, given current trends, to drive them altogether extinct. What might actually be a bigger impact is the role of humans in giving certain species chances to speciate. For instance, rats travel on human ships, which allows them to reach places they couldn't before. Domestic house cats are another good example; having been introduced to six out of seven continents (and briefly maintaining a presence in the Antarctic region before being purposely exterminated) and being successful to the point of raising concern for conservation, they might well (assuming they are not eliminated by humans) undergo dramatic speciation. The same can be said for canines – but domestic dogs have already undergone (incomplete) speciation to give rise to dingos and New Guinea singing dogs. This has basically given, to continue using the feline example, an extremely successful mesopredator, formerly restricted to a comparitively limited area, a much larger range with many of the native predators either on the wane or outright extinct due to human-related causes--in a mere two hundred or so years.